Utilization of L-methionine and production of methanethiol by bacteria isolated from raw milk Camembert cheese

Eighty bacterialstrains isolated from the surface of Camembert cheeses prepared with raw milk were tested for their capacity to produce methanethiol.With the exception of two strains identified as Straphylococcus xylosus, the only strains able to produce methanethiol from L-methionine in sufficient quantities to be of possible technological interest were orange coryneform bacteria related to Brevibacterium linens.Only strains able to produce methanethiol could develop on minimal medium containing L-methionine or c-ketobutyrate as carbon source.This character may be used as a screening test when studying surface cheese flora.These results are discussed in relation to the role of B. linens in the ripening process of cheeses with surface flora.